Before putting a shovel or trencher into the ground, irrigation contractors need a clear plan to ensure that their irrigation system is installed correctly.
The first on the list is to dial 811 to mark the utility on the property. Next, the irrigation contractor needs to know what they will dig.
Knowing the type of soil is important because some areas may be rocks and additional tools or equipment may be required to bury the pipe to the proper depth. Jason Fuller, president of Red & White Greenery in Georgetown, Texas, said soil also affects the man-hours and watering time required to prevent runoff in these areas.
The company provides irrigation, landscaping, hardscape, site furnishings, masonry and commercial maintenance. 80% of Fuller’s customers are commercial customers and 20% are residential customers. The company’s annual revenue is US$11 million.
When installing the irrigation system, make sure that the pipeline is compacted and the sprinklers are installed to the slope. (Photo courtesy of Jainism)
The irrigation plan should specify all aspects of the system, including the type, size, and location of backflow preventers; trunk pipe size and general location; valve size and location; sideline size and general location; and irrigation head type, nozzle size, and location.
Fuller said they should check the flow and pressure of the flowmeter, which will change the design of the irrigation system. The installer must also consider the outline of the property and the different types of irrigated vegetation.
Rain Bird’s senior contractor account manager Steve Barendt said that visiting the property prior to installation allows the contractor to flag any conflicts between the landscape plan and the actual site.
“Adjust as needed to ensure that the available flow rate in the area is not exceeded,” Barente said. Mark any changes made during installation on the as-built drawings.
Although the depth of the trench will vary according to local regulations and geographic location, there are general guidelines. Steve Hoveln, senior product manager for rotors, valves and fittings at Hunter Industries, said that in residential properties, acceptable pipe depths are 8 to 12 inches.
He added that for commercial projects, the main line is often about 18 to 24 inches deep, and the side line from the valve to the nozzle is installed shallower, about 8 to 12 inches.
Once the system is up and running, you can make small adjustments to the system. (Photo courtesy of Hunter Industries)
Hoveln said that when using pipes with gaskets on commercial properties, contractors must consider higher flow rates, which can cause angle damage if not handled properly. Every time the pipe rotates 90 degrees, the installer should add a thrust block, wrap the entire fitting in concrete or install a block behind it as a support.
After the valve is set and the pipe is connected, connect the swing joint to the rotor, and then adjust it to a suitable height. After adding the nozzle, the installer can start to adjust the rotor to the proper arc to avoid overspraying on hard landscapes or buildings. Barendt said that you can make some adjustments before running the zone, but the zone should be run to fine-tune it.
Jain Irrigation marketing manager Michael Derewenko said that although backfilling seems simple, there is an appropriate way to bury the pipeline.
Hoveln said that if the property is rock and the PVC pipe is laid in a trench, the sharp rocks may wear the pipe due to slight vibrations, causing problems. Creating a sand bed for the pipe-and backfilling it with sand-will prevent sharp edges from damaging the pipe.
Avoid installing sprinklers directly on hard PVC, because the base will break when lawn mowers or vehicles run over them. To allow the nozzle to move, a pre-made swing joint should be used-or a hose with a length of 18 to 24 inches, depending on the grade.
The lateral direction should run in parallel, not on top of each other as much as possible, because the recently filled ditches do not have the strength provided by the compacted soil. If heavy machinery travels on newly buried pipelines, the pipelines may squeeze each other, causing thin lines that are difficult to see to break. Derewenko said the contractor should also ensure that trash and debris are not left in the ditches.
“The biggest problem is to leave trash and debris in the ditches. Not only will this add trash to the site, but after the pipeline is installed, the rock will pierce the pipe,” Derewenko said. “In addition to keeping debris outside the ditches, it is best to take the newly added soft soil to ensure that the pipeline is compacted and sprinklers are installed to make it level and point in the right direction.”
Barendt says that incorrect nozzle selection is another common mistake. For example, a contractor can install a No. 2 or No. 3 nozzle on each rotor in an area. Since all the rotors discharge the same amount of water and rotate at the same speed, the 90-degree rotor will get twice the amount of water as the 180-degree rotor because it covers the arc twice and one cover once in the time required for 180 degrees .
“It also means that if there is any 360-degree rotor in the middle of the yard, it will only cover the arc once — and the 90-degree rotor in the corner will cover four times,” Barente said. “The result is that the wet corners are overwatered and/or the center area is dry and underwater.”
The solution to this problem is to determine the size of the nozzle and space according to the manufacturer’s guidelines. Barendt added that changing the nozzle size will also change the distance it throws, so the space and size can be covered with the correct size nozzle for proper head-to-head coverage.
By using high-quality technology and products, installers can ensure that the system can be used for decades and save costs for customers.
Fuller added: “One of the main benefits of a properly designed and installed irrigation system is that customers can effectively irrigate their property, saving them time and most importantly, saving money.”
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Post time: Jul-03-2021
